The weather was closing in. For a week, cryosphere scientist Luke Trusel and his team hadn’t been able to access their remote drill site in western Greenland, and if they didn’t act now, there was no telling when they’d get another chance.

Spying a brief window where helicopter flight was safe, the researchers grabbed only minimal gear and made for the camp, where they drilled an ice core – their deepest of the season – in a straight 24-hour stretch, breaking only briefly to sleep in a cramped, chilly tent.

It was worth it. The results of their polar all-nighter confirm that Greenland’s massive ice sheet – the leading source of new water added to the ocean every year – is melting faster than at any point in recent centuries. And probably far beyond.

“Melting of the Greenland ice sheet has gone into overdrive,” Trusel, from Rowan University in New Jersey, told ScienceAlert.

“It’s now melting more than at any point in at least the last four centuries, and probably more than at any time in the last 7 to 8 millennia.”

In this case, Trusel’s team used multiple cores to piece together a record of the last 364 years of melting ice in Greenland, giving us an unprecedented perspective on the epic ice sheet’s fade to blue.

What they found is that increases in melting intensity began shortly after the onset of industrial-era Arctic warming in the mid-1800s, but it’s during a much more recent timeframe that things got really wet.

Results from two of the cores “show a pronounced 250 percent to 575 percent increase in melt intensity over the last 20 years, relative to a pre-industrial baseline period,” the authors write in their paper.

“Furthermore, the most recent decade contained in the cores (2004–2013) experienced a more sustained and greater magnitude of melt than any other 10-year period in the ice-core records.”

(Sarah Das/Woods Hole Oceanographic Institution)

In other words, the melting is increasing dramatically. But it’s not just picking up speed in a straight line – the analysis shows the melting is accelerating in a non-linear curve.

“The chart of runoff looks like a hockey stick,” Trusel says.

“Melting has not just increased, it’s accelerating in response to a warming atmosphere. This means warming is more impactful today than it was even 50 years ago.”

According to Trusel, the most concerning part of this anomalous acceleration is we haven’t seen the worst yet. Far from it.

“This response has recently exceeded anything we’ve seen for the last four centuries, and it will continue to respond to today’s warmth for decades, centuries, or millennia,” he says.

“Because ice sheet melting in response to a warming atmosphere increases exponentially, this means the sea level rise we’ve seen already will pale in comparison to what might be expected in the future as climate continues to warm.”

If there’s a silver lining in these grim findings, it’s that now we have an overview of the Greenland ice sheet’s long-term melting behaviour, maybe – just maybe – we can do something about it.